Substrate processing apparatus and semiconductor device producing method

ABSTRACT

Disclosed is a substrate processing apparatus, including: a processing chamber for processing a substrate; a substrate rotating mechanism for rotating the substrate; a gas supply unit for supplying gas to the substrate, at least two kinds of gases A and B being alternately supplied a plurality of times to form a desired film on the substrate; and a controller for controlling a rotation period of the substrate or a gas supply period defined as a time period between an instant when the gas A is made to flow and an instant when the gas A is made to flow next time such that the rotation period and the gas supply period are not brought into synchronization with each other at least while the alternate gas supply is carried out predetermined times.

This application is a Divisional of application Ser. No. 10/592,348,filed on Oct. 11, 2007 now U.S. Pat. No. 7,950,348, the entire contentsof which are hereby incorporated by reference and for which priority isclaimed under 35 U.S.C. §120.

TECHNICAL FIELD

The present invention relates to a substrate processing apparatus and aproducing method of a semiconductor device, and more particularly, to asubstrate processing apparatus and a producing method of a semiconductordevice which process a semiconductor substrate using gas.

A general CVD apparatus forms a film on a substrate by keeping reactiongas flowing for a given time. At that time, the substrate is rotated insome cases to eliminate influence of a distance (short or long) from agas supply port and to enhance the consistency of film thickness overthe entire surface of the substrate. In such a case, generally, the filmforming time is sufficiently long as compared with the rotation period,and the substrate is rotated many times when the film is formed becausegas is supplied continuously. Therefore, it is unnecessary to take therotation period into consideration strictly.

On the other hand, when gas is supplied periodically, it is necessary totake into consideration a relation between gas supply port and rotationperiod. For example, according to a film forming method called ALD(Atomic Layer Deposition), two kinds (or more kinds) raw material gasesused for forming films are alternately supplied onto a substrate onekind by one kind under given film forming condition (temperature, timeor the like), the gases are allowed to be adsorbed one atomic layer byone atomic layer, and a film is formed utilizing surface reaction.According to this ALD method, when two gases A and B alternately flow,the film forming process proceeds by repeating the following cycle:supply of gas A→purge (remove remaining gas)→supply of gas B→purge(remove remaining gas).

Assume that the time required for one cycle is defined as gas supplyperiod T (seconds) and a rotation period of a substrate is defined as P(seconds). If the supplying cycle of gas and the rotation of a substrateare in synchronization with each other, i.e., if a numeric value of anintegral multiple of T and a numeric value of an integral multiple of Pmatch with each other, and if the matched numeric value is defined as L(seconds), gas is supplied to the same point of the substrate at time L(see FIG. 1), and a case in which the consistency cannot be enhancedoccurs contrary to the purpose of eliminating the influence of distancefrom the gas supply port by means of rotation.

Hence, it is a main object of the present invention to provide asubstrate processing apparatus capable of preventing or restraining thereaction gas supply period and the rotation period of a substrate frombeing brought into synchronization with each other, thereby preventingthe consistency of thickness of a film formed on the substrate over itsentire surface from being deteriorated. It is also an object of theinvention to provide a producing method of a semiconductor device.

According to one aspect of the present invention, there is provided asubstrate processing apparatus, comprising a processing chamber forprocessing a substrate; a substrate rotating mechanism for rotating thesubstrate; and a gas supply unit for supplying gas to the substrate, atleast two kinds of gases A and B being alternately supplied a pluralityof times to form a desired film on the substrate, a controller forcontrolling a rotation period of the substrate or a gas supply perioddefined as a time period between an instant when the gas A is made toflow and an instant when the gas A is made to flow next time such thatthe rotation period and the gas supply period are not brought intosynchronization with each other at least while the alternate gas supplyis carried out predetermined times.

According to another aspect of the present invention, there is provideda substrate processing apparatus, comprising a processing chamber forprocessing a substrate; a substrate rotating mechanism for rotating thesubstrate; a gas supply unit for supplying gas to the substrate, atleast two kinds of gases A and B being alternately supplied a pluralityof times to form a desired film on the substrate, and a controller forcontrolling a rotation period of the substrate or gas supply time suchthat the alternate supplying operation of the gases A and B is carriedout predetermined times between the instant when the gas A is suppliedto an arbitrary location of the substrate and the instant when the gas Ais supplied to the arbitrary location of the substrate next time.

According to still another aspect of the resent invention, there isprovided a substrate processing apparatus, comprising a processingchamber for processing a substrate; a substrate rotating mechanism forrotating the substrate; and a gas supply unit for supplying gas to thesubstrate, at least two kinds of gases A and B being alternatelysupplied a plurality of times to form a desired film on the substrate,and a controller for controlling a rotation period P of the substrate ora gas supply period T defined by a time period between the instant whenthe gas A is made to flow and the instant when the gas A is made to flownext time such that the gas supply period T and the rotation period Psatisfy the following equation (1):|mP−nT|>≠0 (n and m are natural numbers)  (1)

(wherein >≠0 means that truly greater than 0, and ∥ represents anabsolute value).

According to still another aspect of the resent invention, there isprovided a substrate processing apparatus, comprising a processingchamber for processing a substrate; a substrate rotating mechanism forrotating the substrate; a gas supply unit for supplying gas to thesubstrate; and a controller for controlling the rotating mechanism andthe gas supply system such that a supply cycle of the reaction gas and arotation period of the substrate do not come into synchronization witheach other more than a given time when the reaction gas is supplied tothe reaction chamber periodically.

According to still another aspect of the resent invention, there isprovided a producing method of a semiconductor device, comprising with asubstrate processing apparatus, comprising: a processing chamber forprocessing a substrate; a substrate rotating mechanism for rotating thesubstrate; and a gas supply unit for supplying gas to the substrate, atleast two kinds of gases A and B being alternately supplied a pluralityof times to form a desired film on the substrate, wherein the substrateprocessing apparatus further comprises a controller for controlling arotation period of the substrate or a gas supply period defined as atime period between an instant when the gas A is made to flow and aninstant when the gas A is made to flow next time such that the rotationperiod and the gas supply period are not brought into synchronizationwith each other at least while the alternate gas supply is carried outpredetermined times, processing the substrate.

According to still another aspect of the resent invention, there isprovided a producing method of a semiconductor device, comprising with asubstrate processing apparatus, comprising a processing chamber forprocessing a substrate; a substrate rotating mechanism for rotating thesubstrate; and a gas supply unit for supplying gas to the substrate, atleast two kinds of gases A and B being alternately supplied a pluralityof times to form a desired film on the substrate, wherein the substrateprocessing apparatus further comprises a controller for controlling arotation period of the substrate or gas supply time such that thealternate supplying operation of the gases A and B is carried outpredetermined times between the instant when the gas A is supplied to anarbitrary location of the substrate and the instant when the gas A issupplied to the arbitrary location of the substrate next time,processing the substrate.

According to still another aspect of the resent invention, there isprovided a producing method of a semiconductor device, comprising with asubstrate processing apparatus, comprising a processing chamber forprocessing a substrate; a substrate rotating mechanism for rotating thesubstrate; and a gas supply unit for supplying gas to the substrate, atleast two kinds of gases A and B being alternately supplied a pluralityof times to form a desired film on the substrate, wherein the substrateprocessing apparatus further comprises a controller for controlling arotation period P of the substrate or a gas supply period T defined by atime period between the instant when the gas A is made to flow and theinstant when the gas A is made to flow next time such that the gassupply period T and the rotation period P satisfy the following equation(1):|mP−nT|>≠0 (n and m are natural numbers)  (1)

(wherein >≠0 means that truly greater than 0, and ∥ represents anabsolute value), processing the substrate.

BRIEF DESCRIPTION OF THE FIGURES IN THE DRAWINGS

FIG. 1 is a diagram used for explaining a gas supply state when arotation period of a substrate to be processed and a gas supply periodcome into synchronization with each other.

FIG. 2 is a diagram used for explaining a gas supply state when arotation period of a substrate to be processed and a gas supply perioddo not come into synchronization with each other.

FIG. 3A shows a film thickness distribution when the substrate to beprocessed is not rotated.

FIG. 3B shows a film thickness distribution when the substrate to beprocessed is rotated and the rotation period of the substrate to beprocessed and gas supply period come into synchronization with eachother.

FIG. 3C shows a film thickness distribution when the substrate to beprocessed is rotated and the rotation period of the substrate to beprocessed and gas supply period does not come into synchronization witheach other.

FIG. 4 is a schematic longitudinal sectional view for explaining avertical substrate processing furnace of a substrate processingapparatus according to one embodiment of the present invention.

FIG. 5 is a schematic transversal sectional view for explaining thevertical substrate processing furnace of the substrate processingapparatus according to the one embodiment of the present invention.

FIG. 6 is a schematic perspective view for explaining the substrateprocessing apparatus body according to the one embodiment of the presentinvention.

PREFERABLE MODE FOR CARRYING OUT THE INVENTION

In a preferred embodiment of the invention, the rotation period P andthe gas supply period T are finely adjusted to satisfy the followingequation (1):|mP−nT|>≠0 (n and m are natural numbers)  (1)

(wherein >≠0 means that greater than 0, and ∥ represents an absolutevalue).

If the equation (1) is satisfied, it is possible to prevent the supplystart timing of gas A during the gas supply period from coming intosynchronization with a rotation position of the substrate (see FIG. 2),and the consistency can be improved.

If the time span during which the equation (1) is satisfied is takeninto consideration, it is of course sufficient if the equation (1) issatisfied for the entire film forming time, but the condition may beweakened a little, and it is conceived that there is no problem in termsof consistency if the synchronization is not established for a time spancorresponding to 10 cycles (10T (seconds) if the above symbol is used),for example, because the gas injection timing is sufficiently dispersed.

Embodiment 1

The following description is based on an example in which DCS(SiH₂Cl₂,dichlor-silane) and NH₃ (ammonia) are alternately supplied twice ormore, and an SiN (silicon nitride) film is formed on a silicon wafer bythe ALD method.

When a rotation period P of a wafer is 6.6666 seconds and a gas supplyperiod T is 20 seconds, since 3×6.6666=20, time 20 seconds required forthree rotations becomes equal to the gas supply period T. Therefore, ifthe wafer is rotated three times, the rotation period of the wafer andthe relative position of a gas supply nozzle become the same, the gas isadversely supplied to the same location again, and a thickness of thefilm at its portion located upstream of the gas flow is increased. FIG.3B shows a film thickness distribution at that time. A left portion ofthe film is thick, and a portion of the film from its right side towardthe right lower portion becomes thin. It can be found that when a waferis rotated, the distribution becomes concentric and the consistency isenhanced, but if the rotation period of the wafer and the gas supplyperiod come into synchronization with each other, such effect cannot beobtained. If the wafer is not rotated, the thickness consistency overthe entire surface of the wafer is 12% (see FIG. 3A), and the thicknessconsistency over the entire surface of the wafer when thesynchronization is established is about 7% (see FIG. 3B).

The thicknesses in FIGS. 3A and 3B are different from each other. Thisis because that since the wafer in FIG. 3B is rotated, when the thickportion becomes close to a nozzle of DCS, DCS is supplied.

On the other hand, when the rotation period P of the wafer is 6.6666seconds and the gas supply period T is 21 seconds, the DCS injectingtiming does not come into synchronization with the first injection until1,260 seconds are elapsed. As many as 60 cycles have been carried out sofar, the injection of the DCS is sufficiently dispersed, and concentricfilm thickness distribution having no deviation is obtained as shown inFIG. 3C. When the rotation period of a wafer and the gas supply periodare not in synchronization with each other until so many cycles arecarried out, the consistency of film thickness of the wafer over theentire surface thereof is improved to 3.7% (see FIG. 3C).

FIG. 4 schematically shows showing a structure of a vertical typesubstrate processing furnace according to this embodiment, and is avertical sectional view of a processing furnace portion. FIG. 5schematically shows showing a structure of the vertical type substrateprocessing furnace according to this embodiment, and is a transversesectional view of the processing furnace portion. A reaction tube 203 asa reaction container for processing wafers 200 which are substrates isprovided in a heater 207 which is heating means. A lower end opening ofthe reaction tube 203 is air-tightly closed with a seal cap 219 which isa lid through an O-ring 220 which is a hermetic member. At least theheater 207, the reaction tube 203 and the seal cap 219 form a processingfurnace 202. The reaction tube 203 and the seal cap 219 form a reactionchamber 201. A boat 217, which is a substrate holding means, stands fromthe seal cap 219 through a quartz cap 218. The quartz cap 218 is aholding member which holds the boat. The boat 217 is inserted into theprocessing furnace 202. A plurality of wafers 200 to be batch-processedare multi-stacked in an axial direction of the tube in their horizontalattitude. The heater 207 heats the wafers 200 inserted into theprocessing furnace 202 to a predetermined temperature.

The processing furnace 202 is provided with two gas supply tube 232 aand 232 b as supply tubes for supplying a plurality of kinds (here, twokinds) of gases. From the first gas supply tube 232 a, reaction gas issupplied into the processing furnace 202 through a first mass flowcontroller 241 a which is flow rate control means, a first valve 243 awhich is an open/close valve and a buffer chamber 237 formed in thelater-described processing furnace 202. From the second gas supply tube232 b, reaction gas is supplied to the processing furnace 202 through asecond mass flow controller 241 b which is flow rate control means, asecond valve 243 b which is an open/close valve, a gas reservoir 247, athird valve 243 c which is an open/close valve, and a later-describedgas supply unit 249.

The processing furnace 202 is connected to a vacuum pump 246 which is anexhaust means through a fourth valve 243 d by means of a gas exhausttube 231 which is an exhaust tube for exhausting gas, and the processingfurnace 202 is evacuated. The fourth valve 243 d is an open/close valve.By opening or closing the fourth valve 243 d, the processing furnace 202can be evacuated or the evacuation can be stopped. The opening degree ofthe fourth valve 243 d can be adjusted using pressure.

A buffer chamber 237 is provided in an arc space between the wafers 200and an inner wall of the reaction tube 203 constituting the processingfurnace 202. The buffer chamber 237 is a gas dispersing space extendingin a stacking direction of the wafers 200. The buffer chamber 237extends along the inner wall from a lower portion to an upper portion ofthe reaction tube 203. An end of a wall of the buffer chamber 237adjacent to the wafers 200 is provided with first gas supply holes 248 afor supplying gas. The first gas supply holes 248 a are opened toward acenter of the reaction tube 203. The first gas supply holes 248 a havethe same opening areas from the lower portion to the upper portion, andthe holes are provided at the same pitch.

A nozzle 233 is disposed at an end of the buffer chamber 237 oppositefrom the end at which the first gas supply holes 248 a are provided. Thenozzle 233 is disposed along the stacking direction of the wafers 200from the lower portion to the upper portion of the reaction tube 203.The nozzle 233 is provided with second gas supply holes 248 b forsupplying a plurality of gases. When a pressure difference between thebuffer chamber 237 and the processing furnace 202 is small, the openingareas of the second gas supply holes 248 b may be the same and theopening pitches may be the same from its upstream side toward itsdownstream side, but if the pressure difference is great, the openingareas may be increased or the opening pitches may be reduced from theupstream side toward the downstream side.

In this invention, if the opening areas or the opening pitches of thesecond gas supply holes 248 b are adjusted from the upstream side to thedownstream side, gases can be injected substantially at the same flowrate although flowing speeds of gases are different from one anotheramong the gas supply holes 248 b. Gas injected from each second gassupply hole 248 b is injected to the buffer chamber 237 and is onceintroduced, and the flowing speeds of gases are equalized.

That is, in the buffer chamber 237, gas particle velocity of gasinjected from each second gas supply hole 248 b is moderated, and thenthe gas is injected into the processing furnace 202 from the first gassupply holes 248 a. During this time, gases injected from each of thesecond gas supply holes 248 b had equal flow rates and flowing speedswhen the gases were injected from the first gas supply holes 248 a.

A first rod-like electrode 269 which is a first electrode having a thinand long structure, and a second rod-like electrode 270 which is asecond electrode, are disposed in the buffer chamber 237 such as toextend from an upper portion to a lower portion in the buffer chamber237. The first rod-like electrode 269 and the second rod-like electrode270 are protected by electrode protection tubes 275 which are protectiontubes for protecting the electrodes. One of the first rod-like electrode269 and the second rod-like electrode 270 is connected to a highfrequency power supply 273 through a matching device 272, and the otherone is grounded (reference potential). As a result, plasma is producedin a plasma producing region 224 between the first rod-like electrode269 and the second rod-like electrode 270.

The electrode protection tubes 275 can be inserted in the buffer chamber237 in a state where the first rod-like electrode 269 and the secondrod-like electrode 270 are isolated from atmosphere in the bufferchamber 237. If the atmosphere in the electrode protection tube 275 isthe same as outside air (atmosphere), the first rod-like electrode 269and the second rod-like electrode 270 respectively inserted into theelectrode protection tubes 275 are oxidized by heat from the heater 207.Thus, there is provided an inert gas purge mechanism which charges orpurges inert gas such as nitrogen into and from the electrode protectiontube 275, reduces the oxygen concentration to a sufficiently low value,and prevents the first rod-like electrode 269 or the second rod-likeelectrode 270 from being oxidized.

A gas supply unit 249 is provided on an inner wall of the reaction tube203 at a location away from the first gas supply holes 248 a through120°. When a plurality of kinds of gases are supplied to the wafers 200alternately one kind by one kind by the ALD method to form films, thegas supply unit 249 and the buffer chamber 237 alternately supply thegases to the wafers 200.

Like the buffer chamber 237, the gas supply unit 249 also includes thirdgas supply holes 248 c for supplying gas at the same pitch to a positionadjacent to the wafer. The second gas supply tube 232 b is connected tothe gas supply unit 249.

When the pressure difference between the buffer chamber 237 and theprocessing furnace 202 is small, it is preferable that the opening areasof the third gas supply holes 248 c are equal to each other from theupstream side to the downstream side and the holes are arranged at thesame opening pitch, but when the pressure difference is great, it ispreferable that the opening areas are increased or the opening pitch isreduced from the upstream side to the downstream side.

The boat 217 is provided at the central portion in the reaction tube203. The plurality of wafers 200 are placed on the boat 217 at themulti-stacked manner at equal distances from one another. The boat 217is brought into and out from the reaction tube 203 by a boat elevatormechanism (not shown). To enhance the consistency of processing, a boatrotating mechanism 267, which is a rotating means for rotating the boat217, is provided. If the boat rotating mechanism 267 is rotated, theboat 217 held by the quartz cap 218 is rotated.

A controller 121 is a control means. The controller 121 is connected tothe first and second mass flow controllers 241 a and 241 b, first tofourth valves 243 a, 243 b, 243 c and 243 d, the heater 207, the vacuumpump 246, the boat rotating mechanism 267, a boat vertically movingmechanism (not shown), the high frequency power supply 273 and thematching device 272. The controller 121 adjusts the flow rates of thefirst and second mass flow controllers 241 a and 241 b, opens and closesfirst to third valves 243 a, 243 b and 243 c, opens and closes thefourth valve 243 d and adjusts the pressure of the fourth valve 243 d,adjusts the temperature of the heater 207, starts and stops the vacuumpump 246, adjusts the rotation speed of the boat rotating mechanism 267,controls the vertical motion of the boat vertically moving mechanism,controls the electricity supply to the high frequency power supply 273,and controls impedance by the matching device 272.

Next, an example of forming a nitride film (SiN film) using DCS(SiH₂Cl₂, dichlor-silane) and NH₃ gas by the ALD method will beexplained.

First, wafers 200 on which films are to be formed are placed on the boat217, and the boat 217 is brought into the processing furnace 202. Then,the following three steps are carried out.

Although DCS is first allowed to flow into the furnace in the followingexample, a method in which NH₃ is allowed to flow first is alsosubstantially the same.

(1) A desired amount of DCS is previously stored in a state where 243 bis opened and 243 c is closed (it is preferable that raw material isstored in the gas reservoir 247 previously at the first cycle, and afterthe second cycle, the raw material is stored in the gas reservoir 247 atany time except at event in which the raw material from the gasreservoir 247 is discharged so as not to waste the time).

(2) Before DCS stored in the gas reservoir 247 is discharged, it ispreferable to previously flow inert gas such as N₂ from the bufferchamber 237. This avoids an adverse case in which DCS stored in the gasreservoir 247 flows into the reaction tube 203 in a rush due to thepressure difference between the gas reservoir 247 and the reaction tube203 in the next event, and the DCS back flows into the buffer chamber237 from the gas supply port 248 a of the buffer chamber 237.

(3) By opening the valve 243 c located downstream from the gas reservoir247, DCS stored in the gas reservoir 247 is supplied to the wafers 200which are substrates to be processed, from the gas supply ports 248 cformed in the buffer chamber (gas supply unit) 249, each providedbetween the substrates through the buffer chamber (gas supply unit) 249.The pressure of the adjusting means (valve 243 d such as a butterflyvalve provided in an intermediate portion of an exhaust tube) ofpressure in the furnace is set high so that the partial pressure of DCSbecomes high so as to facilitate the adsorption of raw material. In thiscase also, it is preferable to keep flowing inert gas such as N₂ fromthe buffer chamber 237. The wafer temperature at that time is 300 to600° C.

(4) The valve 243 c is closed and the supply of DCS to the gas reservoir247 is stopped. After the valve 243 c is closed, the time elapsed untilthe next supply starts can be used for storing DCS (that is, since DCSgas can be stored in the gas reservoir 247 while another event is beingcarried out, it is unnecessary to prepare extra time for an event ofonly storing).

(5) Next, DCS is removed from the reaction tube 203 and the bufferchamber (gas supply unit) 249 by the vacuum exhaust means 243. At thattime, it is effective for replacing gas by adding an inert gas linebetween the valve 243 c and the buffer chamber (gas supply unit) 249,and combining a push-out operation by means of inert gas and anevacuation operation.

(6) Next, NH₃ is supplied into the buffer chamber 237 from the gassupply tube 232 a through the nozzle 233 connected to the buffer chamber237. At that time also, it is preferable to flow inert gas from thebuffer chamber (gas supply unit) 249 for the same reason as thatdescribed above.

(7) The NH₃ is supplied to the buffer chamber 237 from the nozzle 233such that the pressure in the buffer chamber 237 becomes uniform. TheNH₃ is supplied to the wafers 200 as the substrates to be processed fromthe gas supply holes 248 b formed in the buffer chamber 237 such thateach gas supply hole is located between the adjacent substrates. If thisembodiment is used, it is possible to supply NH₃ to the plurality ofwafers 200 as the substrates to be processed in the same manner.

The temperature of the heater 207 at that time is set such that thewafers 200 are heated to 300 to 600° C. Since the NH₃ has high reactiontemperature, the NH₃ does not react at the wafer temperature. Therefore,the NH₃ is plasma-excited and allowed to flow as active species.Therefore, the reaction can be carried out in the set low wafertemperature range.

(8) The supply of NH₃ into the reaction tube 203 is stopped.

(9) Next, the removing operation of the NH₃ from the reaction tube 203and the buffer chamber 237 is carried out by an exhausting operationcarried out using the vacuum exhausting means 243. In this case also, itis effective to combine a push-out operation by means of inert gas andan evacuation operation.

The operations (1) to (9) correspond to one cycle, and by repeating theoperations (1) to (9), the film forming process proceeds.

In an ALD apparatus, gas is adsorbed on a backing film surface. Anadsorption amount of gas is proportional to the pressure of gas andexposed time of gas. Therefore, in order to allow a desired given amountof gas to be adsorbed in a short time, it is necessary to increase thegas pressure in a short time. In this aspect, in the embodiment, thevalve 243 d is closed and DCS stored in the gas reservoir 247 issupplied instantaneously. Therefore, the pressure of DCS in the reactiontube 203 can be increased abruptly, and a desired given amount of gascan be adsorbed instantaneously.

In this embodiment, while DCS is stored in the gas reservoir 247, NH₃ isplasma-excited and is supplied as the active species and gas isexhausted from the processing furnace 202. These operations arenecessary steps in the ALD method. Therefore, a special step for storingDCS is not required. Gas is exhausted from the processing furnace 202,NH₃ gas is removed and then DCS is allowed to flow. Therefore, NH₃ gasand DCS do not react with each other on the way to the wafers 200. Thesupplied DCS can effectively react only with NH₃ which are adsorbed onthe wafer 200.

Next, referring to FIG. 6, an outline of the semiconductor producingapparatus, which is one example of the semiconductor producing apparatusto which the present invention is applied, will be explained.

A cassette stage 105, which functions as a holding tool delivery memberwhich delivers a cassette 100 (a substrate accommodating container)between a casing 101 and an external transfer apparatus (not shown), isprovided on a front surface side in the casing 101. A cassette elevator115 which functions as an elevator means is provided on a rear side ofthe cassette stage 105. A cassette loader 114 which functions as atransfer means is mounted on the cassette elevator 115. A cassette shelf109 which functions as a placing means of the cassette 100 is providedon the rear side of the cassette elevator 115, and an auxiliary cassetteshelf 110 is provided also above the cassette stage 105. A clean unit118 is provided above the auxiliary cassette shelf 110 so that clean aircan flow into the casing 101.

The processing furnace 202 is provided above a rear portion of thecasing 101. A boat elevator 121 which functions as an elevator means isprovided below the processing furnace 202. The boat elevator 121vertically moves the boat 217, which functions as the substrate holdingmeans, to and from the processing furnace 202. The boat 217 holds thewafers 200 as substrates in the multi-stacked manner in their horizontalattitudes. The seal cap 219 is mounted as a lid on a tip end of avertically moving member 122 which is mounted on the boat elevator 121,and the seal cap 219 vertically supports the boat 217. A loadingelevator 113 is provided as an elevator means between the boat elevator121 and the cassette shelf 109. A wafer loader 112 which functions as atransfer means is mounted on the loading elevator 113. A furnace openingshutter 116 which functions as a shielding member is provided by theside of the boat elevator 121. The furnace opening shutter 116 has anopening/closing mechanism and closes a lower surface of the processingfurnace 202.

In the cassette 100, the wafers 200 are rotated through 90° by thecassette stage 105 such that wafers 200 are brought into the cassettestage 105 from an external transfer apparatus (not shown) and the wafers200 assume the horizontal attitudes. The cassette 100 is transferred tothe cassette shelf 109 or the auxiliary cassette shelf 110 from thecassette stage 105 by cooperation of vertical movement and lateralmovement of the cassette elevator 115 and forward and backward movementand rotational movement of the cassette loader 114.

The cassette shelf 109 includes a transfer shelf 123 in which cassette100 to be transferred by the wafer loader 112 is accommodated. Thecassette 100 on which the wafers 200 are set is transferred to thetransfer shelf 123 by the cassette elevator 115 and the cassette loader114.

If the cassette 100 is transferred to the transfer shelf 123, the wafers200 are loaded on the boat 217, which is lowered from the transfer shelf123 by cooperation of forward and backward motion and rotational motionof the wafer loader 112 and vertical motion of the loading elevator 113.

If a necessary number of wafers 200 are loaded on the boat 217, the boat217 is inserted into the processing furnace 202 by the boat elevator121, and the processing furnace 202 is air-tightly closed with the sealcap 219. In the air-tightly closed processing furnace 202, the wafers200 are heated, processing gas is supplied into the processing furnace202, and the wafers 200 are processed.

If the processing of the wafers 200 is completed, the wafers 200 aremoved to the cassette 100 of the transfer shelf 123 from the boat 217following the above procedure in reverse, the cassette 100 is moved tothe cassette stage 105 from the transfer shelf 123 by the cassetteloader 114, and is transferred out from the casing 101 by the externaltransfer apparatus (not shown). In the state in which the boat 217 islowered, the furnace opening shutter 116 closes the lower surface of theprocessing furnace 202 to prevent outside air from entering into theprocessing furnace 202.

The transfer motions of the cassette loader 114 and the like arecontrolled by transfer control means 124.

The entire disclosure of Japanese Patent Application No. 2004-70136filed on Mar. 12, 2004 including specification, claims, drawings andabstract are incorporated herein by reference in its entirety.

Although various exemplary embodiments have been shown and described,the invention is not limited to the embodiments shown. Therefore, thescope of the invention is intended to be limited solely by the scope ofthe claims that follow.

INDUSTRIAL APPLICABILITY

As explained above, according to the preferred embodiment of the presentinvention, there is proposed a substrate processing apparatus and aproducing method of a semiconductor device both capable of preventing orrestraining the reaction gas supply period and the rotation period of asubstrate from being brought into synchronization with each other,thereby preventing the consistency of thickness of a film formed on thesubstrate over its entire surface from being deteriorated.

As a result, the present invention can especially preferably be utilizedfor a substrate processing apparatus and a producing method of asemiconductor device which process a semiconductor substrate, such as asemiconductor Si wafer, using gas.

The invention claimed is:
 1. A substrate processing apparatus,comprising: a processing chamber for processing a substrate; a rotatingmechanism for holding and rotating the substrate in the processingchamber; a gas supply unit for supplying processing gas into theprocessing chamber; at least one pair of electrodes disposed in theprocessing chamber for generating plasma to excite the processing gassupplied into the processing chamber by being applied with highfrequency electric power; and a controller that controls the rotatingmechanism and the gas supply unit such that a supply cycle of theprocessing gas and a rotation period of the substrate do not come intosynchronization with each other when the processing gas is periodicallysupplied into the processing chamber.
 2. A substrate processingapparatus, comprising: a processing chamber for processing a substrate;a rotating mechanism for holding and rotating the substrate in theprocessing chamber; a gas supply unit for supplying processing gas intothe processing chamber; an exhaust unit for exhausting atmosphere in theprocessing chamber; and a controller that controls the rotatingmechanism, the gas supply unit and the exhaust unit, wherein the gassupply unit includes a gas supply path connected to the processingchamber and a gas supply valve for opening and closing the gas supplypath, the exhaust unit includes an exhaust path connected to theprocessing chamber and an exhaust valve for opening and closing theexhaust path, the controller controls the gas supply unit and theexhaust unit such that when the processing gas is supplied into theprocessing chamber, the gas supply valve is opened to supply theprocessing gas into the processing chamber through the gas supply pathin a state in which exhaust of the processing chamber is substantiallystopped with the exhaust valve being closed, and the controller controlsthe rotating mechanism and the gas supply unit such that a supply cycleof the processing gas and a rotation period of the substrate do not comeinto synchronization with each other when the processing gas isperiodically supplied into the processing chamber.
 3. The substrateprocessing apparatus as recited in claim 2, wherein the gas supply unitfurther includes a gas reservoir disposed upstream from the gas supplyvalve for storing the processing gas, and the controller controls thegas supply unit such that after supplying the processing gas into thegas supply path and storing the processing gas in the gas reservoir withthe gas supply valve being stopped, the gas supply valve is opened tosupply the processing gas stored in the gas reservoir into theprocessing chamber.
 4. A substrate processing apparatus, comprising: aprocessing chamber for accommodating substrates arranged in a stackedmanner; a rotating mechanism for holding and rotating the substrates inthe processing chamber; a gas introducing section provided in theprocessing chamber along a stacking direction of the substrates forintroducing processing gas; a buffer chamber that includes a pluralityof gas supply ports arranged along the stacking direction of thesubstrates and that is configured such that the processing gasintroduced from the gas introducing section is supplied from theplurality of gas supply ports into the processing chamber; and acontroller that controls the rotating mechanism and the gas introducingsection, wherein the controller controls the rotating mechanism and thegas introducing section such that a supply cycle of the processing gasand a rotation period of the substrate do not come into synchronizationwith each other when the processing gas is periodically supplied intothe processing chamber.
 5. A producing method of a semiconductor device,comprising: processing a substrate using a substrate processingapparatus including: a processing chamber for processing the substrate;a rotating mechanism for holding and rotating the substrate in theprocessing chamber; a gas supply unit for supplying processing gas intothe processing chamber; and a controller that controls the rotatingmechanism and the gas supply unit such that a supply cycle of theprocessing gas and a rotation period of the substrate do not come intosynchronization with each other when the processing gas is periodicallysupplied into the processing chamber.
 6. A producing method of asemiconductor device, comprising: transferring a substrate into aprocessing chamber; processing the substrate with the substrate beingrotated in the processing chamber and processing gas being periodicallysupplied into the processing chamber; and transferring the substrate outof the processing chamber, wherein in the processing of the substrate, asupply cycle of the processing gas and a rotation period of thesubstrate do not come into synchronization with each other.
 7. Aproducing method of a semiconductor device, comprising: processing asubstrate using a substrate processing apparatus including: a processingchamber for processing the substrate; a rotating mechanism for holdingand rotating the substrate in the processing chamber; a gas supply unitfor supplying processing gas into the processing chamber; at least onepair of electrodes disposed in the processing chamber for generatingplasma to excite the processing gas supplied into the processing chamberby being applied with high frequency electric power; and a controllerthat controls the rotating mechanism and the gas supply unit such that asupply cycle of the processing gas and a rotation period of thesubstrate do not come into synchronization with each other when theprocessing gas is periodically supplied into the processing chamber. 8.A producing method of a semiconductor device, comprising: processing asubstrate using a substrate processing apparatus including: a processingchamber for processing the substrate; a rotating mechanism for holdingand rotating the substrate in the processing chamber; a gas supply unitfor supplying processing gas into the processing chamber; an exhaustunit for exhausting atmosphere in the processing chamber; and acontroller that controls the rotating mechanism, the gas supply unit andthe exhaust unit, wherein the gas supply unit includes a gas supply pathconnected to the processing chamber and a gas supply valve for openingand closing the gas supply path, the exhaust unit includes an exhaustpath connected to the processing chamber and an exhaust valve foropening and closing the exhaust path, the controller controls the gassupply unit and the exhaust unit such that when the processing gas issupplied into the processing chamber, the gas supply valve is opened tosupply the processing gas into the processing chamber through the gassupply path in a state in which exhaust of the processing chamber issubstantially stopped with the exhaust valve being closed, and thecontroller controls the rotating mechanism and the gas supply unit suchthat a supply cycle of the processing gas and a rotation period of thesubstrate do not come into synchronization with each other when theprocessing gas is periodically supplied into the processing chamber. 9.A producing method of a semiconductor device, comprising: transferring asubstrate into a processing chamber; processing the substrate with thesubstrate being rotated in the processing chamber and processing gasbeing supplied into the processing chamber in a state in which exhaustof the processing chamber is substantially stopped; and transferring thesubstrate out of the processing chamber, wherein when the processing ofthe substrate is carried out predetermined times, a supply cycle of theprocessing gas and a rotation period of the substrate do not come intosynchronization with each other.
 10. A producing method of asemiconductor device, comprising: processing substrates using asubstrate processing apparatus including: a processing chamber foraccommodating the substrates arranged in a stacked manner; a rotatingmechanism for holding and rotating the substrates in the processingchamber; a gas introducing section provided in the processing chamberalong a stacking direction of the substrates for introducing processinggas; a buffer chamber that includes a plurality of gas supply portsarranged along the stacking direction of the substrates and that isconfigured such that the processing gas introduced from the gasintroducing section is supplied from the plurality of gas supply portsinto the processing chamber; and a controller that controls the rotatingmechanism and the gas introducing section, wherein the controllercontrols the rotating mechanism and the gas introducing section suchthat a supply cycle of the processing gas and a rotation period of thesubstrate do not come into synchronization with each other when theprocessing gas is periodically supplied into the processing chamber. 11.A substrate processing apparatus, comprising: a processing chamber forprocessing the substrate; a rotating mechanism for holding and rotatingthe substrate in the processing chamber; a gas supply unit for supplyingprocessing gas into the processing chamber; and a controller thatcontrols the rotating mechanism and the gas supply unit such that asupply cycle of the processing gas and a rotation period of thesubstrate do not come into synchronization with each other when theprocessing gas is periodically supplied into the processing chamber.